Traditionally, inkjet printing is accomplished by one of two technologies referred to as “drop-on-demand” and “continuous” inkjet printing. In both, liquid, such as ink, is fed through channels formed in a print head. Each channel includes a nozzle from which droplets are selectively extruded and deposited upon a recording surface.
Drop on demand printing only provides drops (often referred to a “print drops”) for impact upon a print media. Selective activation of an actuator causes the formation and ejection of a drop from a printhead that strikes the print media. The formation of printed images is achieved by controlling the individual formation of drops. Typically, one of two types of actuators is used in drop on demand printing—heat actuators and piezoelectric actuators. With heat actuators, a heater, placed at a convenient location adjacent to the nozzle, heats the ink. This causes a quantity of ink to phase change into a gaseous steam bubble that raises the internal ink pressure sufficiently for an ink droplet to be expelled. With piezoelectric actuators, an electric field is applied to a piezoelectric material possessing properties causing a wall of a liquid chamber adjacent to a nozzle to be displaced, thereby producing a pumping action that causes an ink droplet to be expelled.
Continuous inkjet printing uses a pressurized liquid source connected in fluid communication to a printhead to eject liquid jets from the printhead. Streams of drops are formed from the liquid jets. Some of these drops are selected to contact a print media (often referred to a “print drops”) while others are selected to be collected and either recycled or discarded (often referred to as “non-print drops”). For example, when no print is desired, the drops are deflected into a capturing mechanism (commonly referred to as a catcher, interceptor, or gutter) and either recycled or discarded. When printing is desired, the drops are not deflected and allowed to strike a print media. Alternatively, deflected drops can be allowed to strike the print media, while non-deflected drops are collected in the capturing mechanism.
As the printing industry continues to develop these types of printing systems, aspects of these printing systems are refined in order to maintain various characteristics. For example, as longer printheads (often referred to as pagewide printheads) are developed, printhead components can be refined in order to maintain manufacturing costs at reasonable levels. Nozzle plates, for example, can be thinned or otherwise reduced in thickness while channels that, for example, supply liquid to the nozzles are lengthened or otherwise increased in size. As a result, these printheads tend to be structurally weak so that if the printhead is subjected to mechanical stresses, for example, during packaging or operation, the printhead might sufficiently fatigue and prematurely fail. Throughout this process, there is a desire to maintain printhead characteristics that help to provide acceptable image quality levels during printhead operation.
As such, there is an ongoing effort to improve the structural integrity of printheads while maintaining printhead characteristics that help to provide acceptable image quality levels during printhead operation.